Dogging mechanism for sawmill carriages



Aug. 5, 1930. F. E. MARTIN DOGGING MECHANISM FOR SAWMILL CARRIAGES Filed Feb. 10, 1927 v 2 Sheets-Sheet 1 INVENTOR. 15/29/870 A TTORNE Y.

Aug. 5, *1 930.

F. E. MARTIN DOGGING MECHANISM FOR SAWMILL CARRIAGES Filed Feb. 10, 1927 2 Sheets-Sheet 2 INVENTOR.

A TTORNEY.

Patented Aug. 5, 1930 UNETE. STATES PAJI E FFI'CEi noeerive MECHANISM FOR SAWMILL GARRIAGES' Application filed February 10, 1927; 7 Serial No. 167,277.

This invention is directed to dogging mechanism for use in connection with the knees of a saw mill carriage, and particularly to dogging mechanism of the type wherein the dogs, through manual control, may" Operate at a minimum or maximum distance beyond the face of the knee and wherein the dogs are designed for relative and successive engaging movement under the same power means.

The main object of the present invention is the provision, in a dogging mechanism of the type described, of a guide bar on which the respective dogs are slidably mounted to pcrmit either dog to move substantially throughout the 1 height of the knee, the guide bar being mountedfor operation underpower means for movement toward and from the face of the knee to position the dogs for their maximum or minimum projection. iii A further object of the present invention is the provision of means whereby the movement of the respectiveydogs to a normal or inoperative position is effectively cushioned to absorb the jar and strain on the parts.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of the improved dogging mechanism.

Figure 2 is a section on line 22 of Figure 1.

Figure 3 is a. section on line 3-3 of Fig ure 1.

Figure 4 is perspective view from the side opposite that of Figure 1. Figure 5 is a perspective view of the carrier for the lower dog.

' ure 6 is a perspective view of the carrier for the upper dog.

Figure '7 is a perspective view of the bracket'for the upper end of the slide bar.

Figure 8 is a section on line 8-8 ofFigure' 5. i I I Figure 9 is a view of a' detail: As illustrated, thedogging mechanism of this invention is applied to a knee 1 illustrated conventionally and designed, of course, for the usual movement in the head block, not shown, and otherwise equipped as may be'necessary in the particular instance.

Y The doggingvmechanism proper comprises a guide bar 2 mounted for movement toward and fromthe' face ofthe knee through the medium of upper and lower angle levers 3 and' l; pivotally'mounted at their angle on pivot pins 5 extending laterally from the knee with the terminal of one arm of each lever pivotally connected to the guideba'r, as at 6. and the terminal of the remaining arm connccted'to a rod"7. 1

The upper end. of the rod 7 isconnected to the piston rod 8 of a piston arranged in the cylinder 9 pivotally mounted on a bracket 10 projecting from the guidebar. The cylinder is provided with:s'erviceypipes11 whereby pressure may be admitted to move the cylinder in the desired direction and thus through obvious operation of the angle levers and 4 move the guide bar bodily toward or from the knee. 1 V

The'guide bar is a length to extend substantially from the head block plane of the knee to a point materially abovethe knee, and the respective upper and lower dog blocks or carriers 12 and 13 are slidably mounted on and designed r'or'movement relative to the guide bar 2. f The upper dog. carrier comprises a casting providinga body portion 14L and an upstanding plate 15 havinglateral edges 16 formed or recessed to provide channels 17 to slidably engage the edges of the-guide bar 2. The wall 15inter'mediate the recesses 1'7 is'oifset to provide a channel 18 to snugly receive a slide bar 19 to the lower end of which the upper dog carrier is securely bolted, as at 20. The slide bar 19, hereinafter referred to as the slide. is of somewhat less width than the similar dimension of the guide bar2 andextends upwardly above the upper dog carrier, its upper end being connected to a bracket 21 having guide channels 22 to slidably embrace the edges of the guide bar and a channel 23 to receive the slide. This bracket, which functions to support the dog operating means will later appear, thus cooperates With'the upper dogcarrier to hold the'slide 19in contact'with the guide bar and to guide. such slide vertically of the guide harm the movcment of the upper dog.

The upper dog carrier 12 is tormed witp aloe slide. The spring functions to hold the upper nected the terminal'of a coil spring 29, the

oppositecnd of wliichis secured at to the end of the dog arm at its inward limit thus projecting the dog point outwardly.

As it is desired that the dog point27 be substantially in the'plane of the face of'the knee, or inwardly of such plane when the parts are in inoperative positions, to thereby prevent the dogs being engaged and damaged by the log thrown against the knee, the guide bar 2 is provided at an appropriate point with a cam block 31 having a for wardly and outwardly inclined edge 32 arranged in the path of movement of the pin 28 asthe upper dog is elevated to normal or inoperative position. As the pin 28 rides on the inclined face 32 of the cam blockpthe dog point is moved inwardly relative to the knee, and'is thus positioned substantially in the planeof the face of the knee or inwardly of such face.

The lower dog carrier 13 comprisesa substantially triangular casting, the inner face of which is formed to provide channels 33 to receive and sli'dably cooperate with the edges of the guide bar 2. The bottom edge of the carrier 13 has a transversely extending channelfi l to receive the lower dog arm 35', the latter extending longitudinally of the channel and being secured to. the carrier 13 by'bolts 36. The lower dog arm is provided with the usual dog point 37 which may be integral'or removablysecured to such dog arm. The channel 3 lis so positioned that the lower dog arm, when securedtherein, will he at one side of the guide bar 2, so that the lower dog carrier may move freely longitudinally of the guide bar while carrying the lower dog. j

' The upper and lower dogs are operated through the medium of a pressure cylinder 38 having 'a base casting-39 with a depending web 40 securely bolted to a rearwardly eX- tending Iweb ll of the lower dog. carrier. The cylinder 38. has upper and lower service pipe's' 4-2 leading from any suitable source o f pressure and valve controlled as desired; A piston'43 1S, arranged in'the cylinder, the piston rod it of which extends above the cylinder and is connected to sleeveterminal of the bracket 21 secured to'tlie upper end'of the slide. i

A cushioning means is providedffor the 'parts in moving to inoperative positions,

The upper I such cushioning means including a rod 46 extending through a sleeve terminal 47 of a bracket 48 secured to the outer side of the guide bar at the upper end thereof, this rod e6 extending through an opening l9 in the cylinder base 39 and being provided below the base with a collar 50 and a terminal nut 51 to prevent displacement of the collar. Above the sleeve e7, the rod l6 is encircled by a compression spring 53, the upper end of the rodbeing provided with a washer 54 to bear on the spring and the usual securing and lock nuts 55.

As thus described, it is apparent that the pressure fluid operating means including the cylinder 38 and piston rod 44 are connected to the lower and upper dogs respectively, the

cylinder being connected to the lower dog and the piston rod being connected to the upper dog through tl e connection of such piston rod with the upper end of the slide.

Assuming the parts in the position shown in Figure 1, in which-it will be noted that the guidebar is retracted relative to the face of the knee, inwhich the dogs will be projected at their minimum distance to en gage a board or the like, power is'admitted through one of the service pipes 42 above the piston in the cylinder 38, and'as the piston moves downwardly the upper dog is depressed. As the upper dog moves downwardly, interrupting its cooperation with the cam 31, the spring 29 acts to project the point of the upper dog. T he power movementcontinues until the upper dog engages the upper edge of the board, whereupon the piston becomes the fixed element and the continued application of power causes the cylinder 38 to move upwardly; T his slides the lower dog bodily on the guide bar 2 engage the lower edge of the board.

On admission of power below the piston 43, the reverse operation takes place and the dogs are returned to normal posit-ions. Obviously. in this retur movement, the parts travel under the power augmented by their own weight and hence it is highly important that the cushion effect of the spring 53 be uti ized to counteract the blow. Obviously,

as the parts move to normal position, the

base casting. 39 of the cylinder 38 engages the collar 50, moving the roddownwardly against the tension of the spring and so absorbing'the shock. i If itis desired to project the dogsifor operation at the maximum distance beyond the face of the knee, power is admitted to the cylinder -9.-, the angle levers 3 and 4' moved on their pivots to correspondingly move the slide bar and all connected parts to a position to ISO toward the face of the knee. Thus, when the dogs operated, they will obviously move in a plane beyond the face of the knee which is considerably farther from such knee face than where the guide bar is its limit posi- Lil tion rearwardly of the face of the knee, as indicated in Figure 1. The operation of the dogs for the dogging movement is obviously identical whether the dogs are arranged to operate at a maximum or minimum distance from the face of the knee, it being apparent that all parts of the mechanism are carried by and movable with the guide bar to insure identical operation of the parts in either posi tion of the guide bar.

As will be seen in Figure 2, the base 39 of cylinder 38 is formed with spaced openings, either of which, accordingly as the dogging mechanism is employed on the left hand or right hand side of the knee, may be used to receive the cushioning bar 46. The upper dog has sliding and guided cooperation with the guide bar 2, while the lower dog has a similar sliding and guided cooperation with such guide bar. Normally, the lower dog is slightly below the upper plane of the head block while the upper dog is withdrawn into the plane of or inwardly of the face of the knee. Therefore if, as may happen in cants or quarter saws of peculiarshape, the Vertical movement of the upper dog is comparatively slight before engaging such cant, and an unusually extended upward movement of the lower dog is required to co-,

operate with the cant, it is apparent that the present construction will insure a perfect dogging operation, for no matter where the upper dog may be interrupted in itsdownward movement, the lower dog will thereafter move upwardly to the necessary engaging position, even for example being brought substantially into contact with the upper dog. Therefore, while the structure is designed to accommodate itself to ordinary logs and materials, it is apparent that it is completely flexible to insure active engagement with'any and all types of logs, cants or the like which require unusual movements of either the upper or lower dogs.

that is claimed as new is:

' 1. In a saw mill carriage, a knee, a dogging mechanism including a guide bar carried by the knee, a slide bearing against and movable relative to the guide bar, an upper dog secured to one end of the slide and formed to slidably cooperate with the. guide bar, a bracket carried by the upper end of the slide and formed to slidably cooperate with the guide bar, a lower dog slidably engaging the guide bar, a motor mechanism for operating the dogs and including two relatively movable members, one of said members being carried by the lower dog and the other of said members being carried by the bracket on the slide, and a cushioning member supp by the upper end of the guide bar and cooperating with the member of the motor mechanism carried by the lower dog. I

2. In a saw mill carriage, a knee. a dogging mechanism including a guide bar car .and formed to slidablycooperatewith the guide bar, a lower dog slidably'engaging the guide bar, a motor mechanism for operating the dogs and including two relativelymovfable members, one of said members being carried by the lower dog and the'other of said members being carried by the bracketon the slide, a rod slidably engaging a bracket carriedb the upper end, of theguide bar and eXten ing through anopening formed in the base of the motor mechanism carried by the lower dog, a stop on said rod below said base, and a spring interposed between the upper end of the rod and said bracket, whereby to cushion the movements of the direction.

3. In a saw mill carriage, a knee, a dogging mechanism including a guide bar, means for adjusting the guide bar toward and from the face of the knee, a slide including a bar of somewhat less length than that of the guide bar, said slide being adapted to bear through:

parts in one out on the guide bar, an upper dog mounting I secured to the lower end of the slide and extended to overlie and slidably embrace the edges of the guide bar, an upper dog pivotally arranged in said mounting with a portion thereof to overlie and bear against the edge of the guide bar to limit the projection of the operative end of the dog relative to the guide bar, an independent bracket secured to the upper end of the slide with its edges formed to overlie and slidably embrace the edges of the guide bar, a lower dog mountingformed with channels to slidably receive the edges of the guide bar, a lower dog in said lower dog mounting, a cylinder secured to the lower dog mounting, a piston in the cylinder, and a piston rod extending beyondthe cylinder and secured to the bracket at the the face of the knee, a slide including a bar of somewhat less length than that of the guide bar, said slide being adapted to bear lllB throughout on the guide bar, an upper dog 7 mounting secured to the lower end of the slide and extended to overlie and slidably embrace the edges of the guide bar, an upper dog pivotally arranged in said mounting with aportion thereof to overlie and bear against the edge of the guide bar to limitthe 7 projection of the operative end of the dog.

relative to the guide bar, an independent bracket secured to the upper end of the slide with its edges formed to overlie and slidably V embrace the edges of the guide bar, a lower dog mounting formed with channels to slidtion'on the upper dog to engage the cam block to move the point of the upper dog inwardly relative to the face of the knee in a predetermined position of the slide With respect to the guide bar.

In testimony whereof I afiix'my signature.

' REDERICK E. MARTIN. 

